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            <ol class="chapter"><li><a href="../intro.html"><strong aria-hidden="true">1.</strong> Introduction</a></li><li><ol class="section"><li><a href="../examples/csv.html"><strong aria-hidden="true">1.1.</strong> Example: CSV</a></li></ol></li><li><a href="../parser_api.html"><strong aria-hidden="true">2.</strong> Parser API</a></li><li><ol class="section"><li><a href="../examples/ini.html"><strong aria-hidden="true">2.1.</strong> Example: INI</a></li></ol></li><li><a href="../grammars/grammars.html"><strong aria-hidden="true">3.</strong> Grammars</a></li><li><ol class="section"><li><a href="../grammars/peg.html"><strong aria-hidden="true">3.1.</strong> Parsing expression grammars</a></li><li><a href="../grammars/syntax.html"><strong aria-hidden="true">3.2.</strong> Syntax of pest parsers</a></li><li><a href="../grammars/built-ins.html"><strong aria-hidden="true">3.3.</strong> Built-in rules</a></li><li><a href="../examples/json.html"><strong aria-hidden="true">3.4.</strong> Example: JSON</a></li><li><a href="../examples/jlang.html"><strong aria-hidden="true">3.5.</strong> Example: The J language</a></li></ol></li><li><a href="../precedence.html"><strong aria-hidden="true">4.</strong> Operator precedence (WIP)</a></li><li><ol class="section"><li><a href="../examples/calculator.html"><strong aria-hidden="true">4.1.</strong> Example: Calculator (WIP)</a></li></ol></li><li><a href="../examples/awk.html" class="active"><strong aria-hidden="true">5.</strong> Final project: Awk clone (WIP)</a></li></ol>
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                        <h1 class="menu-title">A thoughtful introduction to the pest parser</h1> 

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                        <a class="header" href="#final-project-awk-clone-wip" id="final-project-awk-clone-wip"><h1>Final project: Awk clone (WIP)</h1></a>
<p>This chapter will walk through the creation of a simple variant of <a href="http://pubs.opengroup.org/onlinepubs/9699919799/utilities/awk.html">Awk</a> (only
loosely following the POSIX specification). It will probably have several
sections. It will provide an example of a full project based on <code>pest</code> with a
manageable grammar, a straightforward AST, and a fairly simple interpreter.</p>
<p>This Awk clone will support regex patterns, string and numeric variables, most
of the POSIX operators, and some functions. It will not support user-defined
functions in the interest of avoiding variable scoping.</p>

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